[client] expose EGL stages in frame latency

Correlate received frames with the texture update actually consumed by
the renderer and retain damage until its token becomes renderable.

Split client latency into dispatch, import, queue, preparation, setup,
effects, desktop, composition, and swap stages in FRAME LATENCY.
Exclude diagnostic overlay work from composition and preserve client
wait time when producer timing is unavailable.

Publish joined samples through a bounded token queue, avoid sleeping
while producer timing is finalized, and correct Wayland photon units.

client/src/overlays.h

@@ -47,15 +47,46 @@ void overlayAlert_show(LG_MsgAlert type, const char * fmt, va_list args);
 typedef struct OverlayFrameTiming
 {
   uint64_t timestamp;
+  uint32_t validMask;
   float    capture;
   float    postProcess;
   float    copy;
   float    ready;
   float    import;
-  float    render;
+  float    dispatch;
+  float    queue;
+  float    prepare;
+  float    setup;
+  float    effects;
+  float    desktop;
+  float    compose;
+  float    swap;
 }
 OverlayFrameTiming;
 
+enum OverlayFrameTimingStage
+{
+  OVERLAY_FRAME_TIMING_CAPTURE,
+  OVERLAY_FRAME_TIMING_POST_PROCESS,
+  OVERLAY_FRAME_TIMING_COPY,
+  OVERLAY_FRAME_TIMING_READY,
+  OVERLAY_FRAME_TIMING_IMPORT,
+  OVERLAY_FRAME_TIMING_DISPATCH,
+  OVERLAY_FRAME_TIMING_QUEUE,
+  OVERLAY_FRAME_TIMING_PREPARE,
+  OVERLAY_FRAME_TIMING_SETUP,
+  OVERLAY_FRAME_TIMING_EFFECTS,
+  OVERLAY_FRAME_TIMING_DESKTOP,
+  OVERLAY_FRAME_TIMING_COMPOSE,
+  OVERLAY_FRAME_TIMING_SWAP,
+  OVERLAY_FRAME_TIMING_COUNT,
+};
+
+#define OVERLAY_FRAME_TIMING_VALID_ALL \
+  ((1U << OVERLAY_FRAME_TIMING_COUNT) - 1U)
+#define OVERLAY_FRAME_TIMING_VALID_PRODUCER \
+  ((1U << OVERLAY_FRAME_TIMING_IMPORT) - 1U)
+
 GraphHandle overlayGraph_register(const char * name, RingBuffer buffer,
     float min, float max, GraphFormatFn formatFn);
 GraphHandle overlayGraph_registerFrameTiming(const char * name,